Tubular continuous-flow steam generator



March 1%, 1937. c. MULLER TUBULAR CONTINUOUS FLOW STEAM GENERATOR Filed April 25, 1935 Christoph Mu ll er lnven tor Attorrvam Patented Mar. it, 1937 commons-now s m m'ron Christoph Miiller, Kasai-mamma Germany, assignor to S chmidtsohe Heissmpfi- Gesellschait m. b. H., Kassel-o Germany Application April 25,

1935, it). taste In G 19, 193% SCIaimS.

In order toprevent with tubular st'eamgenerators operating with positive continuous flow of the working fluid, generally water, the burning of the heating surface of the so called transformation zone in which the liquid is transformedinto steam and which is the-main place .i'or the deposition of salts separated from the hot liquid, it has already been proposed to locate this portion of-the heating surface in a region in which the temperature of the heating gases is comparatively low. There exist, however, sometimes reasons of service which prevent that arrangement, and also the regulation of the heating gases is sometimes connected with difficultiea This invention presents another means for obviating burning of the heating surface ot the trausformation zone,-and it consists in heating the heating surface .(wholly or at least partly) oi 2c the transformation zone in a regulable manner by means of pa part-current of heating gases branched oil fromthe main current thereof; In

this way there isobtained the possibility to regulate in a. simple manner the heating of the transformation zone. 'The heating surface of this zone may be housed, for instance, in a separate spacewhich communicates with the main path of the heating gasesfor the steam generator, and is supplied with regulable quantities of heating gases branched 0% from the main heating gas current by means of a conveying device, for instance a fan or the like. The regulation of the amount of the heating gases may be eflected in dependence of the state of the-steam in the transformation zone, thus, for instance, in dependence ,of the pressure of the steam tr of the temperature of the same, or of the contents of liquid orof moisture in the same, 'or of the mixture of steam and water respectively, there being then provided devices able .to'respond to the action'of one or the other of said causes and to act. in turn, in an appropriate manner-either upon a fan or thelike thatforms a member of" the steam-generating plant, or upon the driving 5 means for the fan eta, viz. upon the engineer motor connected therewith; Another advantage ofthe invention is that the heating of the transformation zone is to certainextent independent of the variations of the load on the steam stantially influencing the heating ofthe mainheating surface. Furthermore, onmodifying the generator itself, as it is posslbleto control the heating of the transformation zone by means of regulatingvalves'or the like-without thereby sub-' (iii. 122-249) drawing, on which similar numerals denote simiv 5 lar parts. Figure 1 is a vertical section through a tubular continuous-flow steam generator designed" according to thisinvention, and Figure 2 is a similar representation showing a modifica- 7 tion. Afurther modification is illustrated in Fig,- ure 3 in a vertical section through a tubular continuous-flow steam generator.

0n the drawing, i (Fig. 1) denotes asubstantially vertical shaft enclosing in its lower portion-a tubular coil 2, in which the water is heated to evaporation temperature by a heating device 3 of anyfsuitable type. The water is introduced 'lntothe coil 2 through the branch t, whereas the steam, that is to s y, finished superheated steam, is withdrawn from the steam generator through the branch 5; The upper portion of the shaft i. is suhdivided, for instance by a vertical wall t, into two chambers l and l which are located "side by side, and of which the one ('1) encloses the heatingsurface 8 of the transformation zone which is, in the example shown, likewise constituted by a tubular coil 8. In this zone the hot water is transformed into steam. There may,

' anyhow, be housed in the chamber 1 also a part of the superheating surface for the steam produced in the'coil t. The final or complete superheating takes place in the coil i'l located in the chemical. The amount of heating gases permitted to stream-throughjhe-chamber i can be varied or regulated, for instance by throttle flaps 9 or by equivalent members, the position of which can be made dependent upon the state of the steam in the transformation zone, for instance J upon the'temperature of the same, there being then provided for this purpose a thermostat (indicated bythe dotted line It) arranged-at any suitable place pertaining. to the transformation zone. The thermostat may, therefore, be connected up to the coil 8 alsoat another place than that selected in Fig.- 1 merely by way of example.

' Instead of making the position of the flaps 9 or their equivalents dependent upon the temperature of the steam, it may be made dependent also upon the pressure of the same, or upon the contents of moisture in the same, allas already mentioned in the preceding part of this specification.

. The waste heating eases escape top" of the shaft. I.

In the modification shown in Fig. 2 the heatthrough the The upper passage I2 is combined with a conveying device ll, for instance a fan or the like, by means of which a part of the heating gases is withdrawn from the shaft I and driven into 10 the chamber ll, through which it flows in'a direction counter to the direction of the steam flowing through the coil 8. The heating .gases get back into the shaft at the bottom of the chamber ll through the passage It. The regu- 5 lation of the heating in this chamber is effected in this case by varying the number of revolutions of said fan, or of the motor or engine driving it, the variations being again made dependentupon the temperature or the pressure, etc.. of the 20 steam, as has already been described. The device affected by the one or the other of said causes is indicated in Fig. 2 by the dotted line I5. There/exists, however, also the possibility to regulate the heating of the zone 8 with the'aid of atmospheric air which can be supplied, for instance, through a branch I6 equipped with a regulating flap II, the position of which may also be made dependent upon the state of the 30 steam, as in the above'mentioned cases. Such a indicated in Fig. 2 by the dotted line 2|. The heating gaseswithdrawn through the branch I! (Fig. 2) may be conducted selectively to the superheating coil I! through the passage 35 I3 (Fig. 2) or to thetop I! of the shaft I as is shown in Figure 3. In thisfigure the tubular coil 8 of the transformation zone is located above the passage i2 through which the part-current of the heating-gases is withdrawn from the shaft 40 I. The passage I! through which the part-current of the heating-gases escapes into the top 19 of the shaft l is arranged in the'upper part of the chamber II. The branched-oi! gases are flowing in this case in the same direction as the steam flowing through the coil 8. The gases are withdrawn from theshaft-as far as possible at it place where their temperature is comparatively I claim:

1. A continuous flow steam generator, comprising a steam generated heating surface, walls defining a main chamber through which the main current of heating gases flows and a second chamber separated from the main chamber, said 55 second chamber enclosing that zone of the cating surface inwhich' the into steam, means for conducting a portion of-the main current of heating gases to said second chamber and leading off the gases therefrom, regulating means responsive to one of the physical properties of-the' steam for controlling the flow of gases through said conductingrneans,

and means for introducing atmospheric airinto said second chamber.

2. A continuous flow steam generator; comprising a steam generating heating surface, walls defining a main chamber through which the main current of heating gases flows and a second chamber separate from -the main Jchamber, means connecting said chambers, said second chamber enclosing that zone of the heating surface in which the liquid is transformed into steam, adjustable regulating means in said connecting means for controlling the fiow of a por- 15 tion of the main stream of heating gases to said device as affected by the state of the steam is liquid is transformed second chamber, said connecting means also including means to retum said portion of the heating gases to the main. chamber, and means for introducing atmospheric air into said second chamber. I

3. A continuous fiow steam generator, comprising a steam generating heating surface, walls I defining amain chamber through ,which the, main current of heating gases fiows and a second chamber separated from the main chamber, said second chamber enclosing that zone of the heating surface in which the liquid is transformed into steam, means for conducting a portion of the main current of heating gases tdsaid second chamber and leading oil. the gases therefrom,

, regulating means responsive to one of the physical properties of the steam for controlling the flow of gases through said conducting means, means for introducing atmospheric air into said second chamber, and means responsive to some physical property of the steam to control the fiow of said atmospheric air. q 4. A continuous flow steam generator, comprising walls defining a passage for .the main part of the heating gases, a steam generating heating surface, said passage enclosing the major part of said heatingsurface, walls defining a second passage, said second enclosing that zone of the heating surface in which the liquid is transformed into steam, said second zone being arranged in series with said major part of the heating surface, means for conducting a.portion of the main current ofheating gases to said second passage and leading off the gases therefrom, and means to regulate the amount of gases passing through said conducting means.

'5. A continuous fiow steam generator, comprising walls forming a main r w: e-anda second passage, a continuous tube forming a passage for water to be vaporized, said first passage enclosing a portion ofthe tube and the second passage enclosing that portion in. which vaporization takes place, meansto conduct .a portion of the heating gases fmm said first w e to said second passage, and means to regulate the flow of gases to said conducting means.

6. A continuous-flow steam generator, comprising a steam generating heatlngsurface, walls defining a main chamber through which the main current of heating gases flows and a second chamber separate from the main chamber, said first chamber enclosing the major part of said heating surface, said second chamber enclosing that zoneofthe heating surface in which the liquid is transformed into steam, said second zone being arranged in series withsaid-major part of the heating surface, means for conducting a portion of the main current of heating gastn to said second chamber. and leading ed the gases therefrom, and regulating means responsive to one of the physical properties of the steam for controlling the flow of gases through said conducting means.'

7. A continuous-flow steam generator, com- I prising a steam generating heating surface, walls defining a main chamber through which the main current of heating gases flows and a second chamber separate from the main chamber, said first chamber enclosing the maJor part of said heating surface, said second chamber enclosing that zone of the heating surface in which the liquid is transformed into steam, said second zone being arranged inseries with said major part of the heating surface, means for conducting a portion of the main current of heating 75 .0 prising a steam generating heating surface, walls I defining a main chamber through which the main current of heating gases flows and a second chamber separate from the mainchamber, said first chamber enclosing the major part of said heating surface, said second chamber enclosing that zone of the heating surface in which the liquid is transformed into steam, said second zone being arranged in series with said major part of the heating surface, means for conducting a portion of the main current of heatin gases to said second chamberandleading off the gases therefrom, and adjustable regulating means in said conducting means controlled by 10 some physical property of the steam.

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